C4 dicarboxylic acids are used not only for various applications in the food industry, as an acidulant, an antimicrobial agent and a pH modifier, but also as a raw material for synthetic resins and biodegradable polymers, and are industrially valuable substances. Industrially, C4 dicarboxylic acids are produced by either chemical synthesis from petrochemical raw materials or microbial fermentation. Conventionally, a chemical synthesis method has been dominantly used because its lower cost; however, recently, in view of e.g., a sharp increase in material cost and environmental load, the production method by microbial fermentation using a recyclable resource as a raw material has attracted attention.
Fumaric acid, one of the C4 dicarboxylic acids, is known to be produced using a fermentative bacterium such as Rhizopus. Rhizopus utilizes glucose as a carbon source to produce fumaric acid and excretes it to the outside the cell. To date, regarding techniques for increasing production of fumaric acid by Rhizopus, for example, improvement in a culture method and preparation of a highly productive strain by mutation breeding are known. However, genetic background of Rhizopus has not yet been sufficiently studied and thus, it is not easy to develop a technology for improved production of a fumaric acid by Rhizopus through genetic recombination, and the number of reports is few. It is only reported that fumaric acid productivity is improved by introducing a gene encoding pyruvate carboxylase and derived from Saccharomyces cerevisiae, in Rhizopus delemar (Patent Literature 1); and introducing a gene encoding phosphoenolpyruvate carboxylase and derived from Escherichia coli in Rhizopus oryzae (Non Patent Literature 1).    (Patent Literature 1) Chinese Patent Publication No. CN103013843    (Non Patent Literature 1) Metabolic Engineering, 2012, 14: 512-520